Abstract

While the marine fish stocks in the seas surrounding Turkey
are gradually diminishing, inland water resources offer a major scope for
development of freshwater capture and culture fisheries. The potential has been
enhanced by the rapid construction of many dams of irrigational and multipurpose
character. The GAP project in south-eastern Turkey aims at eventually irrigating
75 000 km2 of land. By 1998, irrigated areas in the GAP had already
reached 299 554 ha. GAP is a multipurpose river basin project using the water of
the Euphrates and Tigris and involves the construction of 22 dams. The Euphrates
reservoirs will have a total water surface area of 125 175 ha, and those on the
Tigris 73 298 ha. In 1998, capture fisheries harvested 1 842 tonnes, and
aquaculture produced 290 tonnes in the GAP region. Regarding fisheries, the
existing fish stocks need better protection and rational management, and the
local fishermen/farmers should be trained in capture fisheries methods and in
aquaculture applicable in a variety of waterbodies of irrigation systems. The
existing fishery regulations need to be adapted to the GAP region, which differs
climatically from other regions of Turkey. This concerns especially closed
seasons for individual fish species. Dam managers responsible for water releases
should be made aware of the water requirement for fish spawning
periods.

1. Introduction

Turkey is a large peninsula covering over 800 000
m2. It is surrounded by four seas, the Mediterranean, the Aegean, the
Black Sea, and the Sea of Marmara. From this favourable geographic position its
people have had access to marine fishery resources for centuries. However, with
the current population of 68 million, a sixfold increase in 75 years, and a
similar growth in the neighbouring countries, the marine fish stocks have been
put under increasing pressure. Turkeys marine capture fisheries have
declined to about 500 000 tonnes per year.

Turkey, being the largest country in south-western Asia, has
considerable agricultural potential. Twenty-eight million ha of agricultural
lands, 21.5 million ha of pastures, 83 million heads of livestock all depend on
the rainfall and irrigation. In terms of inland water potential, Turkey has 36
rivers with a total length of 178 000 km, over 200 lakes covering 9 000
km2, 142 reservoirs with total water surface area of 2 276
km2, and 1 000 ponds of a total of 15 500 ha. The two major rivers of
Turkey, Euphrates and Tigris, have an annual discharge of 31.6 km3
and 21.3 km3, respectively. All rivers of Turkey have an annual mean
water discharge of 133.2 km3. At present, 193 dams serve
environmental protection and flood control, and 151 dams serve irrigation. Water
potential by storages is shown in Fig. 1.

Fig. 1 Water potential by storages in
Turkey

2. The southeastern anatolian project
(GAP)

In terms of potential, 8.5 million ha of land can be
economically irrigated. The current major irrigation project under way is the
GAP (Guneydogu Anadolu Projesi), which will eventually result in the irrigation
of 75 000 km2. GAP is a multi-purpose river basin project using the
water of the Euphrates and Tigris and involves the construction of 22 dams. When
completed, the GAP will foster investment activities in south-eastern Turkey.
The GAP project covers entirely or partially eight provinces. It is more than a
mere agricultural project as it includes industry, transportation, tourism,
telecommunications, health care, education and rural and urban housing
infrastructure projects. It will enhance the regions living standard and
income levels, increase productivity and employment opportunities, minimize
emigration from the southeast and contribute to the national export potential
(Ozaslan, 1998).

2.1 Agriculture and water potential of GAP

It is estimated that irrigating 1.7 million ha of land will
require construction of many dams of which those constructed already have a
total water surface area of 129 987 ha (Table 1). The final reservoir water
surface area will reach eventually 198 473 ha. There will also be 2 235 km of
irrigation canals. Nineteen dams will serve several purposes, such as irrigation
and hydropower production (Dursun, 1999). The Euphrates reservoirs will have a
total water surface area of 125 175 ha, and those on the Tigris 73 298 ha. The
total reservoir surface area will be 198 473 ha. The GAP project will result in
an 11 percent increase in agriculture production, and more than double the
personal income. It will provide employment for 3.8 million people, and also
produce 6.99 billion kWh of hydropower annually (Anon., 1999).

Table 1Reservoirs in the GAP project
area

River

Operating (ha)

Under construction (ha)

Planned (ha)

Total (ha)

Euphrates

113 308

5 916

5 951

125 175

Tigris

16 679

-

56 519

73 298

Total

129 987

5 916

62 570

198 473

Of the 7.54 million ha of the GAP land, 43.6 percent is
suitable for agriculture, 29.4 percent for pastures, and 19.2 percent for
forestry. This represents 11.7 percent of the agricultural area, 10.3 percent of
the pastures, and 6.2 percent of the forests of Turkey. By 1998, irrigated areas
in GAP already reached 299 554 ha, of which 193 697 ha were irrigated by state
and 105 587 ha by farmers. The major crops produced are wheat, beans, soybeans,
nuts, sunflowers, sesame and rice. The regions climate is suitable for
double cropping.

Irrigation systems

In the GAP irrigation water is diverted from reservoirs by
canals, from which 95 percent of land is irrigated. The remaining 5 percent of
land is irrigated using other irrigation methods. The irrigation has already had
some side effects, such as salinization of about 20 000 ha of land and rising
ground water levels. It is expected that the situation will not get better
unless precautions are taken.

Freshwater fish production in the GAP and in Turkey

The GAP represents almost 17 percent of the total inland water
resources potential, but the region has a low fish consumption and low fish
production. In 1998, capture fisheries harvested 1 842 tonnes, and aquaculture
produced 290 tonnes in the GAP region (Table 2). This was equal to 3.3 percent
of capture from inland waters of Turkey, and to 1.5 percent of freshwater
aquaculture (Celikkale et al., 1999). Carp (Cyprinus carpio)
dominated the fish production, with 1 200 tonnes, followed by Capoeta
trutta (320 tonnes), and Leuciscus cephalus (78 tonnes).

Table 2Freshwater fish production (in tonnes) in
the GAP project area and in Turkey

Year

GAP region

Turkey

Capture

Culture

Total

Capture

Culture

Total

1980

805

-

805

32 225

-

32 225

1985

988

-

988

45 471

-

45 471

1990

393

10

403

37 315

4 237

41 552

1995

1 276

125

1 401

44 983

13 113

58 096

1998

1 842

290

2 132

54 500

33 290

87 790

The Ataturk reservoir is one of the newest reservoirs
constructed. A list of its fish species is given as Table 3. The water quality
for Ataturk reservoir is shown in Table 4.

At present there are eight commercial trout cage-culture
farms. These farms buy fingerlings (weight 50 to 100 g) from other farms for
ongrowing to marketable size within 5-6 months. The culture season extends from
mid-October to mid-May. There are two hatcheries in the GAP region. One of them
is located near the Ataturk reservoir and belongs to the State Hydraulic Works
(DSI). Another is at the Keban dam and also belongs to DSI. Common carp is the
other major cultured fish species. Both hatcheries produce fingerlings for
stocking the reservoirs as well as other waterbodies. Table 5 shows the number
stocked in the GAP reservoirs and the Tigris River in 1999.

3. Discussion

Using irrigation, Turkey has increased the crop and other
agricultural production by about 100 percent. But the agricultural areas, even
though irrigated, are still relatively underutilized, as irrigation practices
are relatively new to farmers. There is a need for training and education of
farmers and managers, especially in the use of irrigation techniques. The
training should include subjects such as double cropping, planting and plant
protection, fertilization, soil analysis, water husbandry, including the dangers
from rising groundwater levels and salinization, integrated pest management,
etc.

Table 4Water quality in Ataturk reservoir (Yuksel
et al., 1998)

Parameter

Value

Year

Jan

Feb

Mar

Apr

May

Jun

July

Aug

Sep

Oct

Nov

Dec

Temperature

°C

1995

12.0

12.0

12.0

16.0

25.0

25.0

25.0

28.0

26.0

22.0

17.0

14.0

1996

11.0

11.0

11.5

15.0

21.0

26.0

28.0

27.5

23.5

19.0

15.0

16.0

Conductivity

mmhos cm-1

1995

332

330

340

332

362

354

349

340

337

310

364

374

1996

381

360

357

370

365

330

305

338

322

326

347

362

Dissolved oxygen

mg/litre

1995

9.9

9.8

8.6

7.9

7.0

6.9

7.1

7.4

8.5

8.4

9.0

9.5

1996

9.9

9.6

9.6

9.9

7.3

7.1

7.1

7.5

8.0

8.3

8.8

9.0

pH

1995

6.75

7.22

7.32

7.15

7.55

7.53

7.56

8.50

8.48

8.68

8.75

8.45

1996

8.31

8.10

8.27

8.48

8.50

7.60

7.88

7.96

8.22

8.25

8.45

7.00

Na

mg/litre

1995

12.1

12.7

14.2

13.2

13.2

12.8

11.9

11.7

11.7

10.0

10.6

9.33

1996

14.7

13.2

13.4

11.2

10.8

9.52

6.47

7.8

11.7

16.1

12.9

13.4

K

mg/litre

1995

1.39

1.35

1.33

1.19

1.14

0.88

0.20

0.24

0.21

0.21

0.21

0.21

1996

1.60

1.47

1.52

1.73

1.21

1.21

1.30

0.91

1.27

3.12

2.01

1.72

NO3

mg/litre

1995

-

1.71

-

2.20

1.77

-

-

-

-

-

-

2.65

1996

1.21

1.08

-

2.60

1.04

-

-

-

-

-

-

1.47

NO4

mg/litre

1995

0.01

0.026

0.41

0.19

0.09

-

0.24

0.05

0.12

0.75

0.75

-

1996

0.22

0.09

-

-

-

-

0.07

-

0.017

-

-

-

Phosphate

mg/litre

1995

-

-

-

0.004

-

0.006

0.006

0.016

0.003

-

-

-

1996

-

-

-

-

-

-

-

-

-

-

-

-

Salinity

%

1995

0.03

0.03

0.03

0.03

0.03

0.03

0.03

0.03

0.03

0.03

0.03

0.03

1996

0.03

0.03

0.03

0.03

0.03

0.03

0.03

0.03

0.03

0.03

0.03

0.03

BOD

mg/litre

1995

0.7

0.8

0.9

0.9

0.7

0.6

0.6

0.4

0.2

0.5

0.2

0.6

1996

1.4

1.2

1.3

1.1

0.9

1.1

1.3

1.2

0.9

1.0

0.7

0.7

Regarding fisheries, the existing fish stocks need better
protection and rational management, and the local fishermen/farmers should be
trained in capture fisheries methods and in aquaculture practices suitable for
application in waterbodies of irrigation systems. The existing fishery
regulations need to be adapted to the GAP region, which differs climatically
from other regions of Turkey. This concerns especially closed seasons for
individual fish species. Dam managers responsible for water releases should be
made aware of water requirements for fish spawning periods. There is also a need
to gradually replace the predominant low-value species by higher value ones in
some waterbodies. Better organization of marketing is also required. A
cooperative approach to problem solving may be suitable for the integration of
capture, processing and marketing of fish.

Aquaculture technologies, such as cage culture, should be more
widely applied, as well as testing new fish species for their suitability for
the new artificial waterbodies.

Finally, a better administrative support is needed, if the
waterbodies serving irrigation in the GAP region are to be fully exploited for
their maximum fish production.

Table 5Fish stocked in 1999 in the GAP reservoirs
and the Tigris River (Safak, 2000)

Reservoir/River

Fingerlings (x1000)

Species

Ataturk reservoir

15 500

Common carp

Karakaya reservoir

2 800 650

Common carp Rainbow trout

Devegeçidi reservoir

1 630

Common carp

Hancaðýz reservoir

680

Common carp

Hacý Hýdýr reservoir

800

Common carp

Dumluca reservoir

980

Common carp

Göksu reservoir

960

Common carp

Çamgazi reservoir

325

Common carp

Kýral Kýzý reservoir

500

Common carp

Tigris river

200

Common carp

Batman reservoir

100

Common carp

Total

24 475 650

Common carp Rainbow trout

References

Anon., 1999. Dams and Hydroelectric Power Plants in
Turkey. Ministry of Energy and Natural Resources. General Directorate of
State Hydraulic Works, Ankara.